I mean why not? Jade Empire allowed it so why not in Andromeda?
I'm not against the concept...... But I don't see how such a thing can be provided inside the confines of a military based plot where the focus of the narrative is supposed to be on the unfolding drama.
Let's put it this way. Person A likes Person B.
Person A and Person B declare undying love.
Person A goes off to fight Person X and Person B is afraid they'll never see Person A again........
The above is a very simple sketch of how to create drama that allows the audience to see a human side to the unfolding action where the action creates opportunities to become involved in the game play by controlling the character. With 3 people, A, B and X, you have a three person triangle that allows for love and conflict to ensue.
Now let's add a fourth person.
Person A likes Person B and Person C.
Person A, Person B and Person C declare undying love.
(Wait, Person A is the player and Love Interests are supposed to fall for the player..... But why do Person B and C love each other? What's their motivation? Out of an ensemble cast which one's are open to the idea? All? Some? We are already on the cusp of Dragon Age 2 bisexual stance on NPC's already here. We could split the NPC's to favour specific other's more than others but what about their character defined values? Do they believe love can exist between more than two people? Or are we just pushing for a reciprocating love triangle because we can"?
Person A goes off to fight Person X and Person B and Person C is afraid they'll never see Person A again........
(Right here is where the idea of a reciprocating love triangle falls down. Imagine how much extra scripting you need to do in the 'marching off to war' speech where you have to either, have it twice as the hero talks to two LI's separately. Or if they are in the same room, cut their dialogue so the two character POV's don't exceed a certain time. Carry Ann Moss's death scene in Matrix 3. The real one. The one that felt like it would never end.... Seriously. Pacing of scene's through the amount of dialogue each character has is crucial to creating good scenes and handing the LI duties off to two character's causes problems in that, as much as the flavour of the LI will change due to character, you don't need more love scenes. Not unless the pllayer is mining the game content as opposed to playing an moviefied RPG shooter where you choose the character's lines. Plus, the focus of the LI is lessened as it's split between two people in a dramatic setting. Who gets left behind? Who gets the 'leaf on the wind - claw through the chest' scene'? Because if you have two LI's then you can lose one and still have an LI to carry on through the game with. Do the two LI's love each other? Do they get their own interactions? Move in together? Are they living separately? All things that are extras to consider coding into the game which aren't necessary when the LI interactions are between two people.
Going into threesome territory will needlessly complicate a story that will already have a large amount of content you will not see on a first play through and pulls energy out of the drama to focus on managing two LI's).
This time the above is a more complicated depiction of love and conflict that needs more screen time to develop. And while BW don't shy away from the need to intimacy, that's not where BW need to devote development time to create a core game.
If the question is, why not two LI's? The answer is, because it's going to needlessly distract from the plot of the game by putting the player in a situation where a love interest is more likely to be in the player's vision. How those tow LI's will interact with each other is more dialogue to create, record and edit, and fanning that out to cover, 4, maybe 6 characters is a large investment of time and effort taken away from developing a core game. Plus..... I just don't see the demand for it from the player fan base.